Shigeo Chiarai attends Itan Private High School, progressing from Class 1-1 in his first year to Class 3-3 in his third. Born on July 8th, his zodiac sign is Cancer. He possesses short, fluffy hair typically secured by three hairpins on the right side and is usually seen in the standard Itan uniform. Chiarai maintains a consistent friendship with Sonoda Taisei and Shinobino Mono. Together, they hold conversations rating their classmates' dating potential, particularly noted in Volume 6, Chapters 75 and 77. These interactions ultimately lead them to establish the Delusion Club. Chiarai is also a member of the Makeru-chan fan club. His surname, Chiarai, functions as a pun derived from the Japanese term "charai" (チャラい), referencing traits of frivolity, flippancy, or flashiness in appearance or behavior.